Structural and Nanomechanical Homogeneity of FDM 3D-Printed PVA Tablets: Drug Incorporation for Controlled Release

The use of 3D-printed tablets for drug delivery has recently gained significant attention [1]. In this study, we have used commercially available polyvinyl alcohol (PVA) filaments (Smartfil PVA, Smart Materials 3D, based on Mowiflex C17, Kuraray) to incorporate model drugs from saturated solutions in absolute ethanol. Biocompatibility assays were conducted on the filament using HaCaT cells to confirm its non-toxic properties using an MTS assay. Cell viability on the material surface was 80.96 ± 5.13%, while cells treated with extracts from the material showed a viability of 102.57 ± 5.23%, indicating that the material is non-cytotoxic. Loading the filament with fluorescein using a saturated ethanolic solution enabled the production of luminescent printed tablets using a Creality Ender 6 FDM 3D Printer [2]. However, when attempting to load previously printed pristine PVA tablets, the printed layers disaggregated when the immersion time was prolonged. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) of 3D-printed tablets made from pure PVA and fluorescein-loaded PVA filaments revealed differences in their thermal degradation behavior. X-ray photoelectron spectroscopy (XPS) data confirmed the semicrystalline nature of the pristine PVA tablets. The percentage of crystallinity decreased when the sample was loaded with fluorescein by immersion, but increased when using a fluorescein-loaded PVA filament to obtain the fluorescein-loaded tablets. Fast Fourier Transform Infrared Spectroscopy (FT-IR) on the 3D-printed tablets allowed us to identify the incorporation of fluorescein and its impact on the PVA chemical structure for the different tablets. Atomic Force Microscopy (AFM) and Ultrasonic Force Microscopy (UFM) provided valuable insights into the nanoscale morphology and elastic homogeneity of the 3D-printed samples.

[1] H. Iqbal, Q. Fernandes, S. Idoudi, R. Basineni, N. Billa, Polymers 16, 386 (2024).

[2] A. Goyanes, A. B. M. Buanz, A. W. Basit and S. Gaisford, Int J Pharm 88 (2014)